This invention relates to automated medical analysis equipment and more particularly to improvements therein.
Since the introduction of a method allowing microscopic examination of individual human chromosomes, the karyotype has emerged as a tool of increasing diagnostic value. Under microscopic examination, the chromosomes, from a somatic cell in the metaphase stage of cell division, appear in scattered disarray. The karyotype is a systematic grouping of metaphase chromosomes from a single cell. This grouping was conceived to assist the geneticist in the identification of individual chromosomes. In normal humans, the 46 chromosomes can be reliably ordered into 24 types (seven groups). The diagnostic value of the karyotype is predicated upon the existence of a consistent pattern in normal patients and the correlation of certain chromosomal aberrations with specific clinical observations. There are two types of chromosomal irregularities: numerical and structural. Numerical aberrations exist when the number of chromosomes in one or more groups differs from the normal case. Structural aberrations manifest themselves in many forms, some presumably unobserved as yet. Those which presently merit nomenclature, amongst others, include variations in arm length and centromere position.
At present, manual karyotyping is so tedious and expensive that its general application is usually limited to those situations involving a suspected abnormality. In these circumstances, the clinical evidence is often so overpowering that the karyotype serves primarily as a corroborative tool. In a addition, manual karyotyping offers little prospect of quantitative data. It is desirable to extend karyotype analysis to the clinically asymptomatic situation. For example, screening all newborns by karyotype may detect certain inherited disorders long before clinical symptoms appear. As the potency and reliability of the karyotype improves, fetal karyotyping through amniocentesis may become a routine part of prenatal care. Screening studies on large populations offer the potential of uncovering the effects of industrial and environmental poisons, aging, and long term low dosage ionizing radiations. These factors may manifest themselves in subtle structural aberrations requiring detailed analysis of the chromosome morphology. The ability to process cells rapidly and inexpensively would also aid in the detection of mosaicism, in which two or more cytogenetically distinct lines of cells exist in the individual.
There are certain functional requirements for an automated chromosome analysis system which should be met before widespread acceptance thereof can be anticipated. One of these is that the system should be compatible with current practice producing results compatible with those obtained with the present manual system of analysis. Further, the system should provide significant time savings in processing cytogenetic specimens without sacrificing accuracy. Its cost should not be prohibitive and it should be accurate.